Project Summary This project will develop new 4D holographic guidance and navigation (4D Visualization) to overcome limitations of conventional imaging methods used to treat aortic stenosis (AS) with transcatheter aortic valve replacement (TAVR). 4D Visualization will improve safety and effectiveness of TAVR over use of x-ray fluoroscopy (?fluoro?) and transesophageal/transthoracic echocardiography displayed on conventional flat 2D monitors. This new method augments dynamic 3D (i.e., 4D) holographic cardiovascular (CV) models (including aortic root, coronaries, left ventricle) with models of TAVR delivery devices to the operative site. This will result in increased accuracy of delivery device positioning leading to fewer complications (e.g., coronary occlusion, heart block, valve regurgitation) as well as lower fluoro radiation dose to patients and staff. This innovation will improve outcomes of TAVR, whose adoption is rapidly expanding as a less invasive, better performing, and more economical alternative to surgical aortic valve repair. In the next 5 years, TAVR is expected to exceed 70% of the aortic valve replacement market and will continue to lead the new era of transcatheter cardiac care. 4D Visualization for TAVR is the first image-guidance method to augment time-varying (i.e., moving) 3D CV holograms to the operative site in real-time registration with a balloon catheter and guidewire. The benefits of combined 4D guidance and navigation are achieved by integrating our electromagnetic (EM) navigation system with guidance provided by Microsoft?s HoloLens, a modern, self-contained, untethered, cost-effective, augmented-/mixed-reality headset. The HoloLens augments ECG-synchronized CV holograms derived from cardiac CT in registration with EM-tracked TAVR delivery devices in patient coordinates. Holographic feedback will improve valve implantation depth and co-axial alignment positioning relative to the aortic root annulus. To demonstrate that 4D Visualization improves TAVR, our feasibility criteria are to increase tracked delivery device positioning accuracy while decreasing fluoro radiation dose. In the bench study (Aim 1), 3D-printed CV models will be integrated with a pulsatile flow circuit to meet the implantation depth and co-axial alignment positioning accuracy criteria. Aim 2 will prove that 4D Visualization meets standard system usability criteria. In the live porcine study (Aim 3), we will show that 4D Visualization, used as an adjunct to fluoro, can significantly increase deployment accuracy while decreasing radiation dose relative to fluoro-alone. Meeting the acceptance criteria will lead to further clinical validation in SBIR Phase II to demonstrate safety, effectiveness, and efficiency of valve deployment using 4D Visualization. Improved valve positioning and overcoming limitations of fluoro-only will pave the way to the full healthcare economic benefits of TAVR over surgical valve repair. The ultimate reach goes beyond aortic valve disease to include transcatheter treatment of other structural heart diseases (e.g., mitral valve stenosis or insufficiency) to further benefit a broader population of patients and caregivers as well as global healthcare economics.